England captain Andrew Strauss issued a warning to his squad on Thursday regarding the dangers of Twitter after Kevin Pietersen's latest spat on the social networking site.

Pietersen, one of England's leading batsmen, was fined an undisclosed sum Wednesday by the England and Wales Cricket Board (ECB) for going on to Twitter to question the credentials of former England international Nick Knight as a Test match commentator of Sky Sports.

Strauss, speaking on the eve of the second Test against the West Indies here at Trent Bridge, said that Twitter was a double-edged sword.

"I'm far too boring to use it!," he joked. "There are always shades of grey with Twitter. It does a really good job of publicising the game but players can find themselves in hot water occasionally.

"There is a line they need to tread with regards to their conditions of employment. We have our own code of conduct and it is manageable.

"You will get occasions when people step out of line and they will be dealt with accordingly," he said.

Pietersen reacted to being fined an undisclosed sum, part suspended for 12 months, by insisting he had nothing against Sky, whose commentary team includes several former England captains.

"Just so as you know, (Michael) Atherton, (Nasser) Hussain, (David) Gower and (Ian) Botham, legends," Pietersen said as he walked into the pavilion after net practice here on Thursday.

Pietersen took to Twitter last week to question the credentials of Knight, who averaged just 23.96 in 17 Tests with one hundred, as a broadcaster.

"Can someone please tell me how Nick Knight has worked his way into the commentary box for the Tests? Ridiculous," said Pietersen, who has 20 Test hundreds to his credit.

Pietersen's comments about Knight were especially sensitive, as Sky agreed in January a new four-year deal to show live international and county cricket believed to be worth at least ?260 million ($408 million) -- the ECB's main source of income.

An ECB statement issued Wednesday said Pietersen had been fined for comments considered to be "prejudicial to the interests of the ECB and a breach of the England player conditions of employment in relation to clauses regarding public statements."

ECB managing director Hugh Morris, himself a former international batsman, is wary of Twitter, once labelling its use by England players as "like giving a machine gun to a monkey".

The 31-year-old Pietersen, 31, had previously taken to Twitter to accuse Knight of "stealing a living" from Sky last year and had also run into trouble after using the site to announce his omission from an England one-day squad.

Knight, who has questioned Pietersen's place in that one-day team, said, in comments reported by the Daily Mail on Thursday: "He (Pietersen) has his opinions and I have had my say about him on a professional basis.

"A lot of it has been full of admiration for the way he plays and I don't see this as a big issue."

The second Test -- in which Pietersen is expected to play -- starts on Friday with England 1-0 up in the three-match series following a five-wicket win over the West Indies at Lord's.